Update travis to hide dependency warnings.

Author: pmienk

.travis.yml

@@ -81,12 +81,12 @@ install:
 script:
 
     # Download and build libbitcoin-protocol and all dependencies.
-    - if [[ $OSX   && $CLANG && $STATIC  ]]; then CC=$CC CXX=$CXX ./install.sh --disable-shared --build-boost --build-zmq --prefix=$TRAVIS_BUILD_DIR/my-prefix; fi
-    - if [[ $LINUX && $CLANG && $STATIC  ]]; then CC=$CC CXX=$CXX ./install.sh --disable-shared --build-boost --build-zmq --prefix=$TRAVIS_BUILD_DIR/my-prefix CFLAGS='-Os' CXXFLAGS='-Os'; fi
-    - if [[ $LINUX && $GCC   && $STATIC  ]]; then CC=$CC CXX=$CXX ./install.sh --build-boost --build-zmq --disable-shared --build-dir=my-build --prefix=$TRAVIS_BUILD_DIR/my-prefix CFLAGS='-Og -g --coverage' CXXFLAGS='-Og -g --coverage'; fi
-    - if [[ $OSX   && $CLANG && $DYNAMIC ]]; then CC=$CC CXX=$CXX ./install.sh --build-zmq --disable-static; fi
-    - if [[ $LINUX && $CLANG && $DYNAMIC ]]; then CC=$CC CXX=$CXX ./install.sh --build-boost --build-zmq --disable-ndebug --disable-static --prefix=$TRAVIS_BUILD_DIR/my-prefix CFLAGS='-Os' CXXFLAGS='-Os'; fi
-    - if [[ $LINUX && $GCC   && $DYNAMIC ]]; then CC=$CC CXX=$CXX ./install.sh --disable-static --build-boost --build-zmq --prefix=$TRAVIS_BUILD_DIR/my-prefix CFLAGS='-Os -s' CXXFLAGS='-Os -s'; fi
+    - if [[ $OSX   && $CLANG && $STATIC  ]]; then CC=$CC CXX=$CXX ./install.sh --enable-isystem --disable-shared --build-boost --build-zmq --prefix=$TRAVIS_BUILD_DIR/my-prefix; fi
+    - if [[ $LINUX && $CLANG && $STATIC  ]]; then CC=$CC CXX=$CXX ./install.sh --enable-isystem --disable-shared --build-boost --build-zmq --prefix=$TRAVIS_BUILD_DIR/my-prefix CFLAGS='-Os' CXXFLAGS='-Os'; fi
+    - if [[ $LINUX && $GCC   && $STATIC  ]]; then CC=$CC CXX=$CXX ./install.sh --enable-isystem --build-boost --build-zmq --disable-shared --build-dir=my-build --prefix=$TRAVIS_BUILD_DIR/my-prefix CFLAGS='-Og -g --coverage' CXXFLAGS='-Og -g --coverage'; fi
+    - if [[ $OSX   && $CLANG && $DYNAMIC ]]; then CC=$CC CXX=$CXX ./install.sh --enable-isystem --build-zmq --disable-static; fi
+    - if [[ $LINUX && $CLANG && $DYNAMIC ]]; then CC=$CC CXX=$CXX ./install.sh --enable-isystem --build-boost --build-zmq --disable-ndebug --disable-static --prefix=$TRAVIS_BUILD_DIR/my-prefix CFLAGS='-Os' CXXFLAGS='-Os'; fi
+    - if [[ $LINUX && $GCC   && $DYNAMIC ]]; then CC=$CC CXX=$CXX ./install.sh --enable-isystem --disable-static --build-boost --build-zmq --prefix=$TRAVIS_BUILD_DIR/my-prefix CFLAGS='-Os -s' CXXFLAGS='-Os -s'; fi
 
 after_success: